virtiolib: Make WDF mem_alloc_nonpaged_block return initialized memory
virtiolib: Make WDF mem_alloc_nonpaged_block return initialized memory

All implementations of mem_alloc_nonpaged_block except for WDF
return zero-inited memory. Make WDF do the same.

This commit fixes ACCESS_VIOLATION BSOD observed in:
https://bugzilla.redhat.com/show_bug.cgi?id=1455488

where mem_alloc_nonpaged_block is called by
virtio_reserve_queue_memory and virtio_delete_queues then
runs before all queues have been fully set up.

Signed-off-by: Ladi Prosek <727f16b97cf99ec0710180d99386e4875fb7e2eb@redhat.com>

gnif/kvm-guest-drivers-windows,daynix/kvm-guest-drivers-windows,vrozenfe/kvm-guest-drivers-windows,YanVugenfirer/virtio-win-arm,YanVugenfirer/virtio-win-arm,virtio-win/kvm-guest-drivers-windows,YanVugenfirer/virtio-win-arm,YanVugenfirer/virtio-win-arm,ladipro/kvm-guest-drivers-windows,YanVugenfirer/kvm-guest-drivers-windows,YanVugenfirer/kvm-guest-drivers-windows,ladipro/kvm-guest-drivers-windows,vrozenfe/kvm-guest-drivers-windows,virtio-win/kvm-guest-drivers-windows,gnif/kvm-guest-drivers-windows,virtio-win/kvm-guest-drivers-windows,YanVugenfirer/kvm-guest-drivers-windows,ladipro/kvm-guest-drivers-windows,daynix/kvm-guest-drivers-windows,gnif/kvm-guest-drivers-windows,virtio-win/kvm-guest-drivers-windows,gnif/kvm-guest-drivers-windows,vrozenfe/kvm-guest-drivers-windows,vrozenfe/kvm-guest-drivers-windows,vrozenfe/kvm-guest-drivers-windows,ladipro/kvm-guest-drivers-windows,virtio-win/kvm-guest-drivers-windows,daynix/kvm-guest-drivers-windows,YanVugenfirer/kvm-guest-drivers-windows,YanVugenfirer/kvm-guest-drivers-windows,daynix/kvm-guest-drivers-windows,daynix/kvm-guest-drivers-windows